Traumatized mammalian optic nerves, as other mammalian central nerves, do not regenerate successfully. The long term goals of the research are to understand what molecular mechanisms are involved in successful nerve regeneration, and what factors promote growth within the damaged mammalian central nervous system (CNS). Study of molecular mechanisms, and their initiation, during regeneration may help to explain why optic nerves, and other nerves of the mammalian CNS, fail to regenerate. Such knowledge should help resolve health problems ranging from blindness to paraplegia. Crushed rat and frog optic nerves will be used to study early molecular events similar to the appearance of a modified protein seen at crush sites in regenerating frog sciatic nerve. Proteins, synthesized and transported from retinal ganglion cell bodies, will be labeled by intraocular injection of 35S-methionine. The processing, or modification, of labeled fast and slow axonally transported proteins at a crush site, will be detected by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and fluorography. Transported protein changes will be studied also in rat retinal cells induced to grow through peripheral nerve grafts and artificial implants. Expression of growth associated proteins (GAPs), resembling those seen in developing and regenerating nerves, will be studied with 2D-PAGE. Factors in peripheral nerve grafts, and other factors known to promote nerve cell growth, will be investigated, initially for their effects on promoting growth of fetal rat retinal cells in culture; and secondly, for promoting growth of rat retinal cell fibres into implants. Fibre growth in the implant will be assessed by silver or neurofilament specific antibody staining. Using 2D-PAGE, the patterns of transported proteins will be compared in growth factor treated and non-treated preparations. The effects of trophic factors on events unique to nerve regeneration will be assessed.